Displaying 1 result from an estimated 1 matches for "a_dfs_last_level_wo_rec".
2018 Jun 11
2
LoopVectorize fails to vectorize code with condition on reduction
...}
The compiler command I used was:
clang -O3 -emit-llvm -S -mllvm -debug -ffast-math A.cpp -fvectorize -mllvm
-force-vector-width=16
Following is the output of LLVM's opt explaining why it fails to vectorize:
LV: Checking a loop in "_Z6Queensi" from A_DFS_last_level_wo_rec.cpp
LV: Loop hints: force=? width=16 unroll=0
LV: Found a loop: for.body
LV: PHI is not a poly recurrence.
LV: PHI is not a poly recurrence.
LV: Found an unidentified PHI. %2 = phi i32 [ 0, %for.body.lr.ph ], [ %4, %for.inc ]
LV: Can't vectorize...